1. Field of the Invention
The present invention relates generally to the field of amorphous alloys. More particularly, the present invention relates to amorphous alloys and alloy structures obtained by controlled crystallization. Specifically, a preferred implementation of the present invention relates to alloys with high number density nanocrystal dispersions that are seeded with an element that is added to the amorphous matrix but that is insoluble therewith. The present invention thus relates to amorphous alloys of the type that can be termed nanocrystal dispersed.
2. Discussion of the Related Art
Historically, rapid solidification processing has yielded amorphous structures in numerous metallic alloy systems. The development of nanocrystalline materials through the partial recrystalization (devitrification) of amorphous precursors has recently received considerable attention.
A first class of amorphous metallic materials that shows particular promise for commercial applications consists of aluminum (Al) glasses that include transition metal (TM) and rare earth (RE) elements. These aluminum glasses possess exceptional strength combined with good ductility and corrosion resistance. These Al-TM-RE glasses typically contain greater than 75 atomic percent (at. %) aluminum. These Al-TM-RE glasses offer an alternative to traditional crystalline materials for some structural applications.
A second class of amorphous metallic materials that shows particular promise for commercial applications consists of iron (Fe) glasses that include transition metal (TM) and rare earth (RE) elements together with boron (B). These iron glasses possess good magnetic properties for electrical applications. These Fe-TM-RE-B glasses typically contain greater than 70 at. % iron.
Those of skill in the art of materials know that changing the size and density of nanocrystals that are produced during initial devitrification can alter the properties of both of these classes of amorphous metallic materials. The controlled crystallization of these alloys is a challenge, as the prior art alloying and heat treatment techniques have remained strictly empirical. Heretofore, there has been no effective approach to precisely and accurately control the number density or dispersion of nanocrystals in an amorphous matrix.
Within this application several publications are referenced by Arabic numerals within brackets. Full citations for these, and other, publications may be found at the end of the specification immediately preceding the claims. The disclosures of all these publications in their entireties are hereby expressly incorporated by reference into the present application for the purposes of indicating the background of the present invention and illustrating the state of the art.